Subjective idealism

Subjective idealism is a philosophical tendency within the idealist outlook that reduces material reality to the contents of individual consciousness, denying the existence of an objective world independent of perception. From a Marxist-Leninist perspective, it represents a reactionary epistemology that mystifies material relations and serves bourgeois class interests by undermining the possibility of scientific knowledge of society.

Classical formulations

George Berkeley's esse est percipi ("to be is to be perceived") exemplifies this position: objects have no existence apart from being perceived. David Hume extended this into radical skepticism, reducing causality and the external world to habits of mental association. Immanuel Kant's transcendental idealism, while claiming "things-in-themselves" (a nouonemon) exist, renders them permanently unknowable, effectively collapsing into subjective idealism by making experience entirely constituted by the subject's categories.

Lenin's Materialism and Empirio-Criticism demonstrates how subjective idealism serves bourgeois ideology by denying objective truth. If reality is merely subjective construction, then claims about exploitation, class struggle, and historical necessity lose their objective basis. This philosophy enables relativism: the capitalist's "truth" becomes as valid as the worker's. By fragmenting reality into isolated subjective experiences, it prevents comprehension of social totality and mystifies the objective class relations that structure experience.

Machism

Ernst Mach and Richard Avenarius attempted to reconcile idealism with scientific positivism, reducing physical objects to "complexes of sensations." Lenin identified this as subjective idealism in disguise, eliminating matter as primary category while claiming scientific rigor. Bogdanov's incorporation of these ideas into Bolshevik theory prompted Lenin's philosophical intervention, recognizing that epistemological confusion threatens revolutionary clarity.

Contemporary Manifestations

Postmodern theories denying objective reality or reducing truth to "discourse" and "social construction" repeat subjective idealist errors in new vocabulary. While correctly noting that knowledge is mediated and situated, they often collapse into the idealist error of denying mind-independent reality entirely. This philosophical position aligns with late capitalist fragmentation, where commodity fetishism reaches such intensity that reification of social relations becomes invisible.

Criticism

Dialectical materialism refutes subjective idealism on multiple grounds:

(1) Practice demonstrates an objective world, we successfully transform material conditions through labor.

(2) Consciousness itself evolved from matter through natural and social development.

(3) Multiple subjects achieve intersubjective agreement about objective features of reality.

(4) Subjective idealism cannot explain why perception is constrained rather than arbitrary. The sensation of hardness when striking stone reflects objective properties, not mere subjective construction.